This note lists the Prime Ministers that have served in the United Kingdom, since 1721.

It notes debate and discussion that took place in the House of Commons, and the media, when the identity of the Prime Minister changed during the course of a Parliament, rather than at a general election, since 1900.

Finally, it lists the locations of Prime Ministerial papers, where known.

Prime Ministers since 1945

Since 1945, the UK has had 15 Prime Ministers.

Nine of those Prime ministers first took office between elections: Winston Churchill (in 1940); Anthony Eden; harold MacMillan; Sir Alec Douglas Home; James Callaghan; John Major; Gordon Brown; Theresa May and Boris Johnson. Four of these continued in office following a general election whilst they were Prime Minister; and one, Winston Churchill, became Prime Minister again, after a period in Opposition.

The other six - Clement Attlee; Harold Wilson; Edward Heath; Margaret Thatcher; Tony Blair and David Cameron - first entered office after a general election (one of these, Harold Wilson, became Prime Minister again, after a period in Opposition).